,
- ,
.
.
2.
.
< v x> =
( )
< v > =
D S , D t.
,
v x =
3.
,
< a x> =
,
a x =
4.
.
n = v2/R; a τ = d v /d t; ,
R .
5. (v = const, a = 0)
= 0 + vt,
0 , t .
6. ( = const)
x = x 0 + v 0 t + at 2/2,
v 0 , t .
v = v 0 + at.
7. ( ) ( ) . :
= f (t).
=
=
, , .
8. (ω = const, ε = 0)
φ = φ 0 +ω t,
φ 0 ; t .
9. - ( )
= t /N;
ν ( )
ν = N / T ν = 1/ ,
N , t,
ω = .
10. (ε = const)
φ = φ0 + ω0 t + ε t 2/2,
ω0 , φ = 2π N.
ω = ω0 + ε t.
11. , :
S = φR; v = wR; a t = eR; a n =
12.
x = A sin(wt+j 0),
x ; ; w - ; j 0 .
13. ,
v = A wcos(w t + j 0) = v msin(ω t + φ0 + π/2).
14. ,
a = A w2sin(w t + j 0) = msin(w t + j 0 + π).
15. :
)
=
|
|
)
16. , (x = A 1cos w t, y = A 2cos(w t + j 0)):
) y = ( D j = 0);
) y = ( D j = p);
) ( D j = p/2).
17.
y = A cos w (t - ),
y t, v .
18. D j D ,
,
l - .
1.
19. , v
.
20.
,
,
- , .
21. , :
)
F = - k x,
- ( ); ;
) - , ;
)
,
m 1 m 2 ; r ( ). G
F = mG;
)
F = mg,
g ;
)
F = m N,
m - ; N .
22.
(i = 2)
,
v 1 v 2 , ; u 1 u 2 , .
23. ,
24. :
)
,
; ;
)
,
g - ; m 1 m 2 ; r ( );
) , ,
= mgh,
g ; h , ( h<<R, R - ).
25.
= + = const,
, .. / (F , F c) = 0.
26.
A = F s cosa,
= D = 2 1,
.
= - Δ, / = 2 1.
2.
27. ,
,
w - .
28.
= I ,
, ; e - ; I .
29. m , :
) l , ,
;
) ( ) , ( );
I = mR 2;
) R , ,
.
30. ,
|
|
I 1w1 + I 2w2 = I 1′w′1 + I ′w′2,
I 1, w1, I 2, w2 , ; I 1′, w′1, I, ′w′2 , .
31. ,
4.1.
1. j = + t +Ct 2 + Dt 3, = 1 , = 0,1 /, D = 0,01 /2. : ) , 3 ; ) ; ) 3 .
.
, 3 , j = j 2 - j 1, j 2 - , 3 (t 2 = 3c); j 1 - t 1 = 0 c.
) j (t) (. ) j 1 j 2:
j 1 = = 1 .
j 2 = + t 22 + Dt 23 = 1 + 0,1×3 + 0,02×32 + 0,01×33 = 1,75 .
j = j 2 - j 1 = 1,75 - 1 = 0,75 .
) 3
) 3
,
w 2 - t 2 = 3 c; w 1 - t 1 = 0 .
= B + 2 Ct + 3 Dt 2.
:
t 2 = 3 . w 2 = 0,1 + 2× 0,2 ×3 + 3×0,01×32 = 0,49 /.
t 1 = 0 c. w 1 = B = 0,1 /.
< e > = /2.
2.
j = 10 + 20 t - 2 t 2.
( ), 0,1 , t = 4 .
.
. , , , , , :
(1)
:
t = e R,(2)
a n = w 2 R, (3)
w - ; e - ; R - .
(2) (3) (1),
. (4)
t = 4
w = (20 - 4×4)-1 = 4 /.
t, , , .
w e (4),
3. v 0 = 1000 / 300 ( ).
: R ; ; ; S, .
:
1. : , .
2. : , , .
, , , : - - . .
0x 0y, , v 0, a, h, S, v b. :
|
|
v 0x = v 0cos a,
v 0y = v 0sina.
. :
v x = v 0x = v 0cos a = const., (1)
S = v x 2 t = (v 0cos a) t, (2)
t - .
:
v y = v 0y - gt = v 0sin a - gt. (3)
h = v 0 t sinα - gt 2/2. (4)
.
1.
n.
.
0 , v y = 0: v x = v 0x = const; , , a t . ,
;
a n = g.
2. h (4), (3):
t h,
3. S , (3)
S = 2 v 0cos a = 2 .
4. . , ( ) 60 , 4 /2.
.
1. II .
.
2. , , , : - ; - ( ). III , : = - .
3.
4. , ( ):
: N - mg = ma.
N
N = mg + ma.
,
P = g(m + a).
:
= 60(4 + 9,8) = 840 .
5. 3 , 300. 50 , , 0,2 /2? 0,1.
.
F
A = F S cos a.,
α . , a = 0 cos a = 1.
1. .
2. .
3. II .
:
, x y, , , - .
4. :
: mg sin a - F + F + 0 = - ma,
y: - mg cos a + 0 + 0 + N = 0,
F = m N,
m - .
F
F = mg sin a + m mg cos a + ma = m (g sin a + m g cos a + a).
5. A = F S = m (g sin a + m g cos a + a) S.
:
A = 3 103 (0,2 + 10×0,5 + 0,1×10×0,87)50 = 900 .
6. , 0,4 100 , 480 / . 1 20 . .
.
D t = Iw 2 - Iw 1,
- ; D t - ; I - ; w 2 - ; w 1 - .
|
|
, :
M.
, - .
7. v 0 = 1 /. = 2 ×104 . u 1 = 800 / a = 300 . m = 20 . u 2 ?
.
1.
2. , .
3.
(M - m) v 0 + mv 0 =
(M - m) u 2 + mu 1cos a,
4. u 2
5.
8. R = 1,5 m 1 = 150 , n = 10 /. m 2 = 60 . , ?
.
1.
I 1w1 + I 2w2 = I 1΄w1΄ + I 2΄w2΄.
2.
(I 1 + I 2) w = (I 1 + I 2΄) w΄, (1)
: I 1 - ; I 2 - , ; w - , ; I 2΄ - , ; w΄ - , .
3. , , :
v =w΄ R. (2)
4. w΄ (1)
(2)
. (3)
5. -
-
I 2 = 0; I 2 = m 2 R 2.
w
w = 2 pn.
6. I 1, I 2, I 2 w (3)
7.
9. 16 6 /. , 10 ?
.
: . .
1. , . (mg) (F ), ,
2. , , , , . .
3.
.
mv 22/2 = 0, ( = F S cos a).
4.
.
5.
10. 98 , 196 . a , ?
.
1. , ( mg F ), . , ( ), .
= const, A = 0.
2. . (. ). I II , , , , h, , a.
3.
I = E II; E I + 0 = 0 + E II; mgh = .
4. , II
1. mgh = ,
2. .
5. ( ):
: , R = l - .
mv 2 )
|
|
F - mg = .
6. , .
: = cos a = l cos a.
h = l - l cos a = l (1- cos a)
h a
F - mg = 2 mg (1- cos a),
cos a = ,
cos a = 0,5; a = 600.
11. N h = 1 , m = 3000 , t = 1 ? .
.
1. , , , .
- () (), - , .
II - I = A ,
= + .
2.
3.
() - 0 = A ,
A - , 0 - I.
4.
A .
5. v II, v 2 - v 02= 2 ah v = v 0 + at, v 0 = 0.
h = v t = (0 + v) t /2,
.
6. v
7.
N = 0,8 .
12. , m R, M. n /. ? , ?
.
(1)
I - ; w - .
I w.
I = I 1 + I 2,
I 1 = - ; I 2 = - . w = 2p n. I 1 I 2 (1)
. (2)
.
(2) n 2 = 2 n 1,
= p 2 4 n 2 R 2(m + 2M) - p 2 n 2 R 2(m + 2M) = 3 p 2 n 2 R 2(m + 2M).
13. m = 0,01 = 2 j 0, . = 0,1 .
: ; x = f (t); F max, .
.
1.
x = A sin w t.
, . , , ,max.
v ,
.
, v max = Aw (cos j =1) ,max
.
, .
.
w = p -1
.
2. :
= 0,045sin pt.
3.
| F max| = ma.
, :
.
( sin w t = 1)
| a | = A w2.
| F max| = mA w2.
F max = 0,01×0,045×3,142 = 4,44 10-3 .
14. , :
x 1 = cosp (t + 1/6),
x 2 = 2cosp (t + 1/2)
( , ).
: , ; .
.
1. :
x = A cos (). (1)
2.
1 = A cos (), (2)
2 = A cos (). (3)
3. (2) (3) (1). : 1 = 1; 2 = 2 .
= pt; = pt; Þ T 1= 2c; T 2 = 2c.
j 01 = p / 6 = 300; j 02 = p / 2 = 900.
: T, , j 0.
1. , T = 2c.
2. . 0y , , . , , , . , .
=
.
j 0.
,
.
:
= 2,6 ; = 2 ; j = 0,4 p .
)
x = 2,6 cos p (t + 0,4) .
15. , :
x = cos pt, (1)
y = 2cos , (2)
( - , - ).
.
.
y = f(x). (1) (2) .
y=2 .
cos p t = x (1),
; = .
y 2 = 2 +2 x.
= | |
-1 | |
-0,75 | 0,1 |
-0,5 | 1 |
1,41 | |
0,5 | 1,73 |
2 |
, x. (1) (2), x 1, y = 2. , -1 +1, -2 +2.
(3) y, , | x | £ 1.
, . , . , . (1) (2)
, = s pt, y = 2cos .
t, | x | y | |
-1 | |||
- 2 | D |
,
- = 4 .
, x, y. .
16. l = 1 3 m 1 D = l /2 m 1. . T .
.
1.
(1)
I - ; m - ; d - ( ) ( ).
2. . I 1 I 2
I = I 1 + I 2. (2)
, , . m = 3m
.
I 2 = I 0 + ma 2,
I2 = ; I 0 - , , ; - .
, I 1 I 2 (2).
.
3. d
4. , (1) I, d, (m = m 1 +3 m 1 = 4 m 1).
= 2,17 .
17. v = 20 /. , l 1 = 12 l 2 = 15 , = 0,1 Dj = 0,75 p. : l; ; t = 1,2 .
.
1. , , l, , 2 p; , D l,
l
,
D l - , 3 .
= 8 .
2.
s = A sin (w t k x),
- 2p/ l,
s = A sin w (t - ).
w,
w,
s = 0,1sin5 p (t - ).
3. s, t l.
s 1 = 0,1sin5p(1,2 - 12/20) = 0,1sin3 p = 0;
s 2 = 0,1sin5p(1,2 - 15/20) = 0,1sin2,25 p = 1sin0,25p = 0,071 .
4.2.
1. R = 4 . S = A + Bt 2, = 6 , = -2 /2. t, n = 9 /2, v, t . (. 1,5 ; -6 /c; -4 /c2; 9,84 /2).
2. : x = A 1 t +B 1 t 2 + C 1 t 3 x 2 = A 2 t + B 2 t 2 + C 2 t 3, 1 = 4 /; 1 = 8 /2; 1 = -16 /3; A 2 = 2 /c; B 2 = -4 /2; 2 = 1 /3. t ? v 1 v 2 . (. 0,235 ; 5,1 /; 0,286 /).
3. m 1 = 10 m 2 = 4 . v 1 = 4 /c, - v 2 = 12 /. u : 1) , ; 2) . , , . (. 6,28 /; -0, 573 /).
4. = 240 m = 60 . v = 2 /. u = 4 /c ( ). : 1) ; 2) , . (. 1/; 3 /).
5. , , . , ? (: 2 , 4 ).
6. , m = 5 . = 1,25 /. D l = 8 . . (. 40 /c).
7. m 1 = 200 , v 1 = 10 /, m 2 = 800 . , , . . (. -6 /; 4 /).
8. , , 64% . , , . ? (. 4 ).
9. , , , . m 1 = 12 . , m 2 = 1 . ? (. 1,4 /2; 8,4 ).
10. , . , m 1= 100 m 2 = 300 . , . , , . (. 3,27 /2; 1,31 ; 1,9 ).
11. , , w = 63 / . , N = 300 . ? (. 1,2 ).
12. h = 90 . , ? (. 3,55 /).
13. , , r = 50 . = 10 , R = 60 . m = 1 . = 0.8 /. ? (. 0,195 /).
14. n 1 = 14 /. . , n 2 = 25 /. m = 70 . , . (. 210 ).
15. h = 3200 . . (. 6,45 /).
16. . = 5 , v = 20 / = -80 /2. , . (. 4 -1; 1,57 ; p /4 ; 7,07 ).
17. , : = sin w t, = 5 , w = 2 -1. ( ), =10-4 , F = 5×10-3 . . (. 2.04 ; 4,07 ).
18. , , , . . (. 1200 2400).
19. , : = A 1cos w 1t y = A 2cos w 2(t + t), 1 = 4 ; 2 = 8 ; w 1 = p -1; w 2 = p -1; t = 1 . . (. 2 + = 0.).
20. v = 15 /. = 1,2 . Dj , 1 = 20 2 = 30 . (. 2000).
1. , , , . ?
:
1) Q, 2) N, 3) M, 4) L, 5)K.
2. h. 80% . , , :
:
1) 0,647 h; 2) 0,947 h; 3) 0,807 h; 4) 0,757 h;5) 0,507 h.
3. 600 . 1 2 ?
:
1) 1 = 4 2; 2) 1 = ¾ 2; 3) 1 = ; 4) <